Well, I suppose you could bully them into doing what you think is best, but I'm not "that" sort of gardener! *laughs*
When it comes to pest control, some of my Clients allow me to use chemicals, some of them positively insist that I use chemicals, and others ask me to use only organic methods, so I get a good chance to see how the various types of pest control stack up against each other.
This is a great example - aphids on Lupins. This year - 2019 - has been an exceptionally good (or bad!) year for aphids of all colours...
...as you can see, the flowering spike of this Lupin is completely swamped with aphids.
Please note the single, lone, brave ladybird....
All the books/articles/internet say things like "if you are troubled with aphids, don't rush for the chemical spray, allow nature time to take its course, and predatory insects such as ladybirds will clean up your problem for you."
Hmmmm, not so much!
I searched a stand of a dozen aphid-infested Lupins, and found a total of three ladybirds, so in my opinion, the aphids are winning.
What do I do about it?
In this garden, which is one of the "we like to be organic" ones, there's not a lot I can do other then get out the hosepipe and jet-wash all the lupins, to blast the little
The hope is that something will eat them, or they will die of starvation, before they manage to clamber their way back up to the tender, soft, stems which they feed on, or should I say, through.
And the jet wash process would need to be repeated every other day, or so, until the infestation was cleared. Not so easy when I don't live there.
In other gardens, where chemicals are allowed, I would have sprayed the plants with a systemic bug killer long before the aphids arrived: that way, the chemicals are contained within the plant, rather than sitting on the leaves, so they only affect anything which bites or probes into the plant, leaving flying and pollinating insects completely unharmed.
In this garden, then, presumably by the end of the week there are going to be three enormous, fat, ladybirds waddling up and down the stalks, burping gently and thinking "Wow! What a great year it's being!"
Or maybe the three of them will be relaxing in the shade of a leaf, one of them playing hot smoky saxophone while the others sing "Summertiiiiiiime, when the living is eeeeeeasyyyyyyy....."